The following are the main biological factors which affect birth:
- Ovulation cycle
a. Age: Human beings become fecund at a certain age. Fecundity begins in women with the onset of menstruation. On average, women are considered fertile from 15 to 45 years of their age. But their fertility performances is not equality active throughout this period. Fertility grows highest in 25-39 age group. Then it begins to slow down gradually. In males too fertility performances is weaker as they grow older, there is not any sharp limit for them as in the female.
b. Health: Health affects all our activities. So, reproduction is also affected by the condition of health of a person. Those who are diseased and unhealthy cannot reproduce well or cannot give birth to a healthy baby. But fecundity is high in those whose healthy is properly maintained.
The following are the economic and socio-cultural factors affecting birth:
- Economic factors:
- Source of income
- Fulfillment of manpower
- Socio-cultural factors :
- God's blessings
- Family structure
- Generational respect
- Sources of income: Poor people consider their children as the source of income. They think that more children will more from different sources. So they produce many children as the only investment they can make.
- Family structure: In a joint family, there are many people of different generation. the burden of bringing up of a children is shared by many of them. So, the parents are encouraged to produce more children.
The psychological factors affecting birth are as follows:
- Prestige of family.
- Sense of completion
- Being a parent is the entire goal
Sense of competition: Most of the Nepalese family is joint family. Any tow brother may have completion in bearing children because they have equal right to the share of their parents property. They can also compete with those others than the ones from their family.